I got this idea from a game called "Company of Heroes" where, basically, a squad carries one highly effective weapon but the price to pay would be to sacrifice the equipment slot (probably the slot for C4's) of 3 or more members of the squad.
Take for example, a Heavy Machine Gun Squad (for this, let's take the M2 Browning HMG as an example). 3 people would need to sacrifice their equipment slot to carry 3 components for the M2 Browning. The gun body itself, the tripod, and the ammunition boxes. These 3 would need to carry each of these components to a specified location to construct the HMG emplacement. The flow would probably go something like this:
- SL places a location for the HMG.
- Squadmates with the components gather around the location and place the components down.
- Once all of the components are in the construction location, a squadmate can hold F on it to begin construction (probably for 30 seconds or a minute) and depending on the amount of people holding F on the construction, it will speed up the process.
- The amount of HMG placements per squad is limited to 1, and every time they place a new one, the old one is despawned.
This doesn't have to be limited to HMG placements as well. Like in Company of Heroes, there are also Mortar squads and Anti-tank gun squads. The more elaborate the weapon is, the more components it needs meaning the more squad members need to sacrifice their equipment slots for the components.
For example, the Mortar squad can probably only need 2 (one carries the mortar itself, another carries the shells, the shells are also affected by the Trophy system and can be nullified). While the Anti-tank gun might need 5 (One carries shells, the 4 carries the gun components: mounting point, the main body/firing system, primary barrel component, secondary barrel component). The amount of ammunition these have can be balanced out for fair gameplay.